Net structures which are intended to stop a torpedo have been used in coastal waters with a high degree of effectiveness as harbor and/or dam protection devices. Generally, these prior art nets have been fabricated from high strength metal cables and have been deployed as static structures in the water environment with anchorages to the ocean floor.
Various of these prior art devices are described and illustrated in the patent art as exemplified by U.S. Pat. No. 2,383,095 (D. A. Wallace); U.S. Pat. No. 2,170,481 (J. J. Morrison et al); and U.S. Pat. No. 2,388,459 (C. S. Allen, Jr.). These known net structures are costly to manufacture and, because of the method of construction and their significant weight, do not lend well to a high packing density for storage onboard light aircraft and/or in the limited spaces of a submarine.
Another known net structure is described and illustrated in U.S. Pat. No. 4,768,417 (J. E. Wright). This net is in the configuration of an active detonator weapon and it is comprised of lengths of nylon rope interwoven with detonator cord. The purpose of the net is to disable a target by way of the explosive detonator cord which is ignited by control packages carried on the net structure. The control packages include initiators for igniting the explosive detonator cord.
With the introduction of smart weapons, ie., acoustic homing torpedos and the like, a need exists for an anti-torpedo device which cannot be detected by these type smart weapons. The anti-torpedo device, therefore, must be passive and comprised of materials which are not ordinarily detectable by conventional methods. The anti-torpedo device must also be economical to manufacture in large quantities and lightweight enough to be carried onboard light aircraft. Furthermore, the anti-torpedo device must exhibit a high packing density for storage onboard aircraft as well as onboard a submarine where space is at a premium.
Therefore, it is in accordance with one aspect of the present invention an object to provide a lightweight, highly packageable, and economically produced passive anti-torpedo device.
In accordance with another aspect of the invention it is an object to provide a passive anti-torpedo net structure comprised of parachute type ribbon materials which exhibit a high structural integrity and the total net structure exhibits a substantially neutral buoyancy when it is deployed into a salt water environment.
In accordance with still another aspect of the invention it is an object to provide an anti-torpedo net comprised of ribbon materials, the ribbon materials being taken from a synthetic group comprising nylon, polyester, aramid, KEVLAR (KEVLAR is a registered trademark of the E. I. Du Pont de Nemours Company of Wilmington, Delaware) and SPECTRA (SPECTRA is a registered trademark of the Allied Chemical Corporation of Norristown, N.J.).